'I'll gut you like a fish in front of all these people': man threatens commuter on Melbourne train

A train passenger has captured a vicious assault where another passenger was shoved, slapped and punched in the face in Melbourne.

The vision from the June 29 incident was released by police on Wednesday, showing a man on a Ringwood-bound train abusing the victim before violently shoving his face into a train window.

The assault at 9.45pm was sparked after it is believed the victim made a comment to the man, who had spent his few minutes aboard from Camberwell Railway Station swearing and making comments to other commuters.

The offender can be seen taunting the man, while his female colleague pushes him away.

Other passengers appear concerned about the confrontation, some intervene, while others change seats to move away from the abusive man.

The offender then returned to his seat and disembarked at the next station, police say.

But the man immediately reboarded, ran at the victim and punched him in the face.

In a video recorded by another passenger, the offender can be heard telling the man: "Don't look at me like you want to fight me," to which he replied: "no I don't".

The man can be heard continuing to taunt the victim.

"I'll f***ing wreck ya, I'll f***ing gut you like a fish in front of all these f***ing people," the offender threatens him.

"I'll f*** you like a whore."

The victim can be heard telling him to stop, as other passengers appear visibly upset by the confrontation.

Some of the passengers intervened and pulled the man off the victim before he broke free and ran off the train.

The victim was left with swelling, bruising and mild concussion.

The man was last seen running over tracks and over a wall at Canterbury Railway Station.

Police have released images and CCTV of a man they want to speak to in relation to the assault.

Anyone who recognises the man or with any information about the incident is urged to contact Crime Stoppers on 1800 333 000.